1. Field of the Invention
The instant invention relates to a power supply system for a pump. More particularly, the instant invention relates to a power supply system for powering a sump pump using either available utility-supplied power or stored power from a battery.
2. Description of the Prior Art
Backup battery power supply systems are known for use with basement sump pumps. One such backup battery power supply is included with the "Basement Sentry Series" line of backup sump pump systems sold by Zoeller Pump Co. This line of backup sump pump systems utilizes a dedicated 12-volt auxiliary pump to supplement the main pump in the event that it cannot operate due to a loss of power or other malfunction. The 12-volt auxiliary pump is powered by a backup battery power supply that provides the required current at 12 volts. FIG. 1 depicts a schematic diagram of this type of system. As seen in FIG. 1, main sump pump 1 is a 110-120 volt pump that receives power from AC receptacle 3. Backup sump pump 5 is a 12 volt pump that receives 12 volt DC power from controller 7a and battery 7b. Transformer 9, which receives AC power from AC receptacle 11, provides DC power to controller 7a to charge battery 7b.
Other similar 12 volt auxiliary pump systems are sold by Simer, Flotec, and Basement Watchdog Special.
A deficiency of all of these 12 volt systems is that due to the relatively low voltage supplied to the sump pump from the battery, a relatively high current is required in order to apply a substantial amount of power to the pump. The transmission of a high current through a medium such as a battery cable is inherently inefficient. Thus, these 12 volt systems do not optimize the use of the stored battery energy in terms of gallons of water that can be pumped in a given time and/or total length of time of pump operation.
Another backup sump pump system is the Sumpro system. While this system utilizes a power inverter to provide 115 volt alternating current to a sump pump from a battery, it is believed that the inverter uses a transformer configuration, which is relatively inefficient. Additionally, the Sumpro system uses a metal enclosure, which is prone to rust in the damp environment in which sump pumps are used. Further, such a metal enclosure may present a potential safety hazard in the event of an internal wiring malfunction resulting in the enclosure being raised to a high voltage state.